The present invention relates to a manually operable folding top for vehicles, and more particularly, to a top with a folded stowed position of the top in the folding-top compartment covered by the folding-top compartment lid and with an unfolded use position of the top in which the folding-top covering is stretched between a roof cap on a front end of the folding-top and a fabric-holding hoop at a rear end of the folding-top, and a closure arrangement comprising a plurality of closures configured to be unlocked with remote control from the vehicle interior and such that the folding-top compartment lid is held closed and the fabric-holding hoop is held down in the position in which it rests on the folding-top compartment lid.
One type of folding top is disclosed in German Patent No. 2,327,487, in which a crank is provided for the remote operation of the hook-type closures used. The crank is connected to the closures of the folding-top compartment lid and of the fabric-holding hoop via connecting rods or Bowden cables. The crank is arranged close to the folding-top compartment in the interior of the vehicle. This allows the closures to be unlocked from an operating point by turning the crank before getting out of the vehicle. This considerably simplifies the operating process when opening the folding top. It is also possible in an advantageous manner to dispense with external operating elements for unlocking the closures.
A disadvantage of the known folding top, however, resides in the fact that there is a considerable outlay for the construction of the hook-type closures themselves and also for the mechanical transmission system between the hand crank and the hook-type closures. In addition, due to the principle of their construction, the hook-type closures have a considerable overall height, especially in the swivelling plane of their closure hook, as a result of which they require a correspondingly deep installation space. If, for example, a recessed closure arrangement for locking the fabric-holding hoop in the folding-top compartment lid is provided, the space for such a deep installation space will hardly be available on the underside of the folding-top compartment lid.
Compact snap-action closures designed as pivoted-latch closures are furthermore used for locking the bonnet in the ranges of motor cars currently made by the assignee of the application, Mercedes-Benz AG. The box-shaped housing of these pivoted-latch closures, in which a forked pivoted latch and a pawl interacting with the latter are mounted, has an overall height of only about 40 mm and thus makes possible a space-saving arrangement of the closure. The snap-action closures, which are in each case used in pairs, are held in their release position by a spring force and can be moved into their locking position by simply pushing the bonnet shut. Their forked pivoted latches are blocked against swivelling in this position by the associated pawl. To unlock the bonnet, the pawls of the snap-action closures are swivelled synchronously out of their locking position. The snap-action closures thereby are released, and their forked pivoted latches snap back into their release position under the spring loading.
For the purpose of remote-controllable release of the closures, a Bowden cable arrangement is provided, via which a handle in the interior of the vehicle is connected to a lever arm of the pawls. The Bowden cable of the Bowden cable arrangement here passes through a narrow side wall of the closure housing, with the result that the overall height of the snap-action closure is not increased by the Bowden cable arrangement.
From the point of view of installation space, it would therefore be worth considering the use of such compact snap-action closures also with lowerable folding tops for the purpose of locking the folding-top compartment lid and the fabric-holding hoop on the folding-top compartment lid, especially since, due to the batch quantities, they can be manufactured relatively economically. However, a multi-element mechanical transmission system would also be necessary for this purpose and it would thus still be necessary to accept the cost of construction of a complex mechanical transmission system. Over and above the cost of construction, a mechanical transmission system between the operating element and the associated closures also quite considerably limits the freedom of the designer in the selection of a suitable operating point.
An object on which the present invention is based is to further provide a manually operable folding top such that space-saving compact closures can be used for the closure arrangement for locking the fabric-holding hoop and the folding-top compartment lid, for the purpose of obtaining, by virtue of a transmission system which is variable and hence economical, a considerable degree of freedom for the engineer in the selection of the operating point for the unlocking of the closures.
The foregoing object has been achieved according to the present invention by providing only automatic-ejection snap-action closures which can be released via a motorized actuating drive, and the actuating drives being actuated via activation of a switch arrangement in order to release the closures. In contrast to known folding-top closures which are locked and unlocked via a motorized actuating drive and are hence of complex construction, as shown, for example, in German Patent 3,708,095, the actuating drives of the present invention provided serve exclusively for releasing the snap-action closure associated therewith. This is important because, as a result, the character of a manually operable folding top is retained. In addition, its actuating force need only be sufficient for the release operation, allowing compact actuators to be used for the actuating drive. Such actuators are used, for example, in central locking systems for the motorized changeover of the security condition of vehicle locks and are therefore manufactured economically in large batch quantities.
Since the snap-action closures eject the closure lug, engaging therein, of the mating component during the release operation, the fabric-holding hoop and the folding-top compartment lid jump up in corresponding fashion, whereupon they can be easily grasped due to the distance therebetween and their distance from the rim of the folding-top compartment.
Ease of operation is made further possible by automatic actuation of the switching device in which a sensor of the switching device can sense a component moved in the first phase of the opening of the folding top. The switching device is preferably actuated at as early a stage as the process of unlocking the roof cap and brings about closure release almost without a time delay.
In order to be able to use the on-board electrical system, present in any case in vehicles, as a transmission system, it is particularly advantageous to release the snap-action closures via electric-motor actuating drives which are activated via one or more electric switches. The actuating drive is expediently provided with an extendable and retractable driving rod which interacts as a tappet with the release mechanism. Such actuating drives, which are known per se, are distinguished by the simple construction of their housing and can therefore be accommodated without problems even in an installation space of little depth.
The flat actuating drive can also advantageously be arranged next to a compact pivoted-latch closure of a type also known per se, interacting with the latter via a release mechanism. A release lever of the release mechanism, which lever can be subjected to shock loading by the driving rod, can advantageously be arranged with a pendular motion between the actuating drive and the closure housing. It thereby is possible to use the interspace for the pendular oscillation of the release lever. The lever length of the release lever can here be dimensioned such that the overall height of the arrangement, as a whole, is at least not significantly increased thereby. A connecting rod passing through the side wall of the closure housing can be guided in a simple manner such that the overall height of the arrangement, as a whole, is not influenced in any way. This connecting rod, which preferably comprises a flexurally stiff metal wire, is furthermore distinguished by a low intrinsic weight and favorable manufacturing costs.
The connecting rod guided in sliding manner above the pawl is expediently engaged around by a driving hook of the pawl. The hook is supported axially on the connecting rod only in the direction of the releasing advance. A U-shaped intermediate bend in the connecting rod itself can then be used for axial support. In order to make possible the articulation of the connecting rod on the release lever at a sufficient distance, in terms of moment, from its oscillation axis, the articulated end region of the connecting rod is preferably offset in an appropriate manner.
By virtue of the special configuration of the release mechanism, a known type of actuating drive can be, in addition, combined in a simple and economical manner with a known, structurally unaltered snap-action closure. Due to the standardization effects possible as a result, the snap-action closure releasable via the electric-motor actuating drive can be constructed relatively economically.